1. Field of the Invention
The present invention relates to the purchase and sale of bandwidth and, more particularly, to a system and method for real-time buying and selling of bandwidth at differentiated quality of service levels, routing of excess traffic over the bandwidth purchased in real time, and billing and settlement of the transactions.
2. Description of the Related Art
The internet is a collection of large nationwide and international networks. Many of the networks are owned and operated by telephone companies such as MCI, Sprint, ANS, and AGIS. Individual users can be directly connected to one of the networks, or indirectly connected via an internet service provider (ISP), typically a company that provides connectivity to one of the networks for a fee.
When two end users are directly or indirectly connected to the same network, data is passed between the users over the common network. If the end users are on different networks, the data is passed from one network to the other network at an interconnection point known as a network access point (NAP).
To provide connectivity to the Internet, the ISP must purchase internet protocol (IP) transit, the right to transmit data onto a network at a specified data rate. For example, IP transit is commonly available at 8 Mbps, 16 Mbps, 34 Mbps, 45 Mbps, and 155 Mbps data rates, and varies in price according to the data rate selected. The higher the data rate, the higher the cost.
The amount of data traffic that an ISP experiences changes dramatically over the course of a day. FIG. 1 shows a graph that illustrates a conventional ISP traffic profile for an ISP that serves business and residential customers, respectively. As shown in FIG. 1, a traffic profile 100 peaks during the middle of the day due to business users, and again peaks in the evening due to personal users.
ISPs are keen to deliver the highest quality of Internet services to their customers. One approach to doing this is to purchase a level of capacity, such as capacity level 112, that insures that sufficient capacity is available during the busiest periods. It is not cost effective, however, for an ISP to merely buy capacity to cope with their peak traffic flow.
As an industry average, ISPs tend to buy 100% more than their average traffic flow. The average traffic flow is defined as the capacity required to cope with the total flow of traffic averaged over a 24-hour period. FIG. 1 shows an average traffic flow level 114, and a doubled (100% more) traffic flow level 116.
As further shown in FIG. 1, doubled traffic flow level 116 is often insufficient to cope with bursty periods, such as bursty periods 118, which are times when traffic flows exceed the available capacity. When the amount of data to be transmitted onto the network is greater than the amount of capacity, the data is stored and output in turn as capacity becomes available. This degrades the service by significantly increasing the time required for the data to be delivered to the end user.
Most ISPs are resigned to this as an inevitable standard tradeoff between quality of service concerns and IP transit costs. Delays for accessing the internet, however, are becoming critical issues for ISPs as customers become more discerning over their speed of internet access.
Thus, ISPs buying IP transit capacity are faced with a dilemma when determining the size of their link. If they over-dimension their network, they will have unused capacity, whilst if they under-dimension their network, they will face frequent overloads that result in poor response times for their customers.
Adding to the dilemma is the approximately 300% to 1000% per year increase in internet traffic. Further, most contracts are for one year, and for blocks of capacity. Thus, ISPs are forced to catch a moving target (the increasing internet traffic) with a wide net (a one year block of capacity).
As a result, ISPs commonly have expensive, unutilized capacity at the beginning of a contract, and degraded quality of service by the end of the contract. Even with over-dimensioning of their IP transit requirements, ISPs are never sure that they will have enough capacity to provide an adequate quality of service during bursty periods that occur at random.
Thus, there is a need for a method that provides high quality internet service during bursty periods that costs significantly less than it would to buy a peak capacity level, such as capacity level 112, and that efficiently responds to increases in demand due to growth.
There are no real solutions within the market, but some players have attempted to address the problem. One approach is to offer usage-based billing, whereby a charge is levied based upon the volume of IP traffic transferred on the network. Another approach is for ISPs to buy monthly contracts for capacity through an exchange.
These exchanges allow networks to advertise their price for a monthly transit service. However, if an ISP does buy such a transit service, they are committed to using it for a month regardless of whether they have sufficient traffic to fully utilize capacity.